12v Stealth Conversion

[RICK IN GA]

I like many on this forum have grown inpatient with our 6v systems in these older Ford Tractors and am looking for a 12v change. I have an 841 that has a 12v Stealth Conversion Generator and it is the most reliable machine I have ever owned. I recently considered converting to an alternator system and read from the Archives john in la"s awesome and very detailed method to convert and was ready to move forward but then I thought I love the appearance of my Stealth. I never found in the archives a pluses and minuses discussion of both systems. Also I never found a wiring diagram or a description of the stealth conversion like john"s with the alt conversion. Anybody have a good 12 volt stealth conversion description and diagram? Thanks!
 

[JMOR]

[RICK IN GA]

What about the coil? I read a lot into what john said about coils and resistance.
 

[JMOR]

[RICK IN GA]

Ooops, what about the starter relay. I want to redo my 54 NAA first and it has a three post. Does it need a 4 post like the diesels? I am fortunate that I have a diesel 881 that I'm redoing (will take a while) that I will temporarily use the genny.
 

[sunbeam]

Just use the coil you have reverse the 2 small wires and add a resister NAPA # MPE ICR13SB or ECH ICR13.
 

[JMOR]

[Will Gumbert]

Rick- If you are just asking about a plus-or-minus comparison of the same system with an alternator vs a generator, the alternator is really the better choice from a technical point of view because it is capable of supplying more current and is more reliable since it does not have brushes carrying the large output current. But, these are vintage machines and I just happen to think it is nice to make them work and look like they originally did. The stealth conversion is nice since you get the advantage of 12v starting ease and easier to find battery, but it looks original.
If your tractor is working well and you do not need to run a lot of electrical accessories, why are you considering changing to the alternator? -Will
 

[RICK IN GA]

Thanks Will, I am a weekend collector and working on 7 of the old Fords. My 841 with the Stealth Conversion is the one that ALWAYS works. It seems historically when I go to the others which are all original 6v I have to put in some level of effort to get them going strong. I have never liked the alternator approach because of the appearance but can"t seem to have reliable 6v tractors. I read on here that it is not so hard to keep the 6v systems running but I haven"t had that kind of luck. Seems like the 12v genny is a great alternative for me.
 

[Will Gumbert]

I agree. Do you have a source for the 12V generators that you would need? You don't necessarily have to use the diesel tractor unit. My 961 has a 12v replacement genny that Ford used as a service part later. Looks like the photo below and mounts kind of upside down with the terminals facing down (maybe could mount right side up too). I have an antique Jeep that has the same generator.
I think I could find the part# if you're interested. -Will



BTW, you asked in your original post about a description of the stealth conversion. I asked the same question and I have inserted below a reply from Tony Jacobs that describes it along with a Pertronix ignition system. Maybe this will help.

Hello Will , All of my Gas Ford Tractors have 12 volt Charging and Pertronix Electronic Ignition systems on them . To do this Stealth Conversion you need a complete/correct unbutchered 6volt wiring harness - change the Generator to the 12volt Diesel unit, connections stay the same, change the Voltage regulator to the 12volt Diesel unit, connections stay the same , change the starter solenoid to the 12volt Diesel unit, connections stay the same . Install the Pertronix kit in the distributor, change to the Pertronix 12volt high voltage coil, and use the Pertronix suppression wires(can't use copper core wires with the Pertronix) it is that easy no cutting of wires no modifications all just bolt together . If you want to leave points in it you have to add the Ballast resistor in before the coil, but it does not start as good in the cold weather as in 20 or 30 degrees below zero, to cure that a 5 leg 12volt starter solenoid(NAPA number ST-83) can be used to run an additional hot 12volt wire to the coil only during the cranking cycle to give the spark a little boost for the cold weather . I have run all three ways in the past 25+years with no problems at all but prefer the Pertronix by FAR, my first Pertronix Conversion on my first 62 841 has over 4000hrs on it with no failures. Thanks Tony
 

[RICK IN GA]

That one looks great! I have to clean up my 881 12v and paint it anyway and it's just like the one on may stealth 841, When looking online It seemed that all 12v gennys were north of $120 unless they said as is. Do you have a good source because I'll need it eventually anyway.
 

[Will Gumbert]

I don't really know of a source for them but I could do some checking and let you know. You could check some of the tractor salvage yards like Long Lane tractors or an auto salvage yard. Even ones that say "as is" might be worth a try if cheap and not missing any major parts. Probably need to stick with Ford or Autolite (B-circuit) as I think the GM units were A-circuit mostly.
Do you have a good auto electrical shop nearby? They might even have them. The local electrical shop in town here told me they could repair them no matter what was wrong with them. You will need a correct pulley but it's possible the one off the 6v genny could work, I don't know. You will also need a suitable regulator.-Will
 

[souNdguy]

that's what my 950 sports.

a genny from a diesel and the coresponding reg. Got them and a small box of other parts from rickb's dead 801d with a window in the engine ( as i recall )
 

[RICK IN GA]

Thanks guys! I think this is the VR called for in my FORD 881/641 diesels CONF10505A. You guys good with this one?
 

[JMOR]